Modeling the Drying of Potato Slices in a Microwave Dryer and Determining the Mass Transfer Parameters

In the present work, the influences of microwave power and samples thickness on the mass transfer parameters of potato slices were studied using the analytical model suggested by Dincer and Dost. Four microwave powers of 200, 400, 600 and 800 W were practiced to dry mono layer of the slices with thicknesses of 3.5, 5, 7 and 9 mm. The Biot number was obtained to be in the range of 1.299–4.096; where decreased following the increment in microwave power and increased with increasing samples thickness. The moisture diffusivity and convective mass transfer coefficient were found to be significantly (P < 0.05) increased with increasing microwave power and the slices thickness, and varied in the ranges of 2.389×10-8–14.681×10-8 m2 s-1 and 2.246×10-5–7.116×10-5 m s-1, respectively. The activation energies for moisture diffusion and surface mass evaporation were determined to be in the ranges of 1.452–1.746 W g-1 and 0.712–1.323 W g-1, respectively.